Numerous attempts have been made to invent a dependable, reliable and economic system for collecting and storing the sun's heat. These systems can be broken down into two major types: passive and active systems.
Passive systems function without the use of external energy. While these systems have the advantage of not requiring an external energy supply, they are inferior to active systems with regard to their capacity to convert sunlight to heat, and to adequately store and transfer the heat as it is needed at the point of use.
Active systems for the collection of heat from sunlight can be divided into two major types: liquid systems, and pneumatic systems.
Liquid systems have the advantage of obtaining slightly greater conversion rates of heat from solar energy. However, liquid systems require greater investments in terms of apparatus and maintenance. They must be protected against freezing in colder climates. A leak in a liquid system can inactivate the entire system, and may flood the surrounding area.
Pneumatic systems, of which this invention is one, have several major advantages: the apparatus may be simple, easily manufactured and assembled, and provide reasonably high conversion of sunlight to heat. A leak in a pneumatic system, while reducing efficiency, neither damages the surrounding environment nor requires the system to shut down.